title: Rust的GRPC实现Tonic toc: true cover: 'https://img.paulzzh.com/touhou/random?3' date: 2022-12-03 14:19:51 categories: Rust tags: [Rust, GRPC]
tonic 是rust中的一个GRPC客户端和服务端的异步实现，底层使用了tokio的prost生成Protocol Buffers对应的代码；
本文讲解了如何使用Tonic，并提供了一个包含多个proto文件的项目案例；
源代码：
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<!--more-->tonic是基于HTTP/2的gRPC实现，专注于高性能，互通性和灵活性；
创建该库的目的是为了对async/await具有一流的支持，并充当用Rust编写的生产系统的核心构建块；
特性：
rustls进行TLS加密支持编译 Protobuf 还是需要安装 protoc 的，可以参考官方文档：
另外，除了这个实现之外，PingCAP 也开源了一个实现：
我试了一下，说实话并没有 Tonic 好用，但是他的 benchmark 稍微高一些；
下面开始编写一个包含多个proto文件的项目案例；
<br/>
最终的目录结构如下：
$ tree .
.
├── Cargo.toml
├── Cargo.lock
├── build.rs
├── proto
│ ├── basic
│ │ └── basic.proto
│ ├── goodbye.proto
│ └── hello.proto
└── src
├── bin
│ ├── client.rs
│ └── server.rs
└── lib.rs
其中：
proto 目录中定义了服务；build.rs 中声明了通过 proto 生成 rs 文件的脚本；lib.rs 中引入了 build.rs 编译 proto 后生成的 rs 文件；bin 目录下定义了客户端、服务端的实现；首先创建一个 lib 项目：
cargo new tonic-demo --lib
在这个 lib 中我们实现服务代码，并通过 bin 目录下的 client 和 server 实现客户端和服务端；
修改 Cargo 配置：
Cargo.toml
[[bin]]
name="server"
path="src/bin/server.rs"
[[bin]]
name="client"
path="src/bin/client.rs"
[dependencies]
prost = "0.11.3"
tokio = { version = "1.19.2", features = ["macros", "rt-multi-thread"] }
tonic = "0.8.3"
[build-dependencies]
tonic-build = "0.8.4"
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创建 proto 目录，并声明相应的服务；
由于网上的资料大多都是一个 proto 文件，而实际项目中基本上都是具有层级结构的；
因此这里我也使用了多个 proto 文件来演示；
定义如下：
// tonic-demo/proto/basic/basic.proto
syntax = "proto3";
package basic;
message BaseResponse {
string message = 1;
int32 code = 2;
}
// tonic-demo/proto/hello.proto
syntax = "proto3";
import "basic/basic.proto";
package hello;
service Hello {
rpc Hello(HelloRequest) returns (HelloResponse) {}
}
message HelloRequest {
string name = 1;
}
message HelloResponse {
string data = 1;
basic.BaseResponse message = 2;
}
// tonic-demo/proto/goodbye.proto
syntax = "proto3";
import "basic/basic.proto";
package goodbye;
service Goodbye {
rpc Goodbye(GoodbyeRequest) returns (GoodbyeResponse) {}
}
message GoodbyeRequest {
string name = 1;
}
message GoodbyeResponse {
string data = 1;
basic.BaseResponse message = 2;
}
在 proto/basic 目录下定义了：BaseResponse；
而在 hello.proto 和 goodbye.proto 中都引入了他；
<br/>
下面来看 build.rs，这也是编译 protobuf 文件的关键！
众所周知，在 build.rs 中定义的代码，会在真正编译项目代码前被执行，用于在编译真正的项目前做一些骚操作；
因此，我们可以在这里先编译 protobuf 文件；
在上面 Cargo 配置中我们引入了：
[build-dependencies]
tonic-build = "0.8.4"
因此在这里被使用：
build.rs
use std::error::Error;
use std::fs;
static OUT_DIR: &str = "src/proto-gen";
fn main() -> Result<(), Box<dyn Error>> {
let protos = [
"proto/basic/basic.proto",
"proto/hello.proto",
"proto/goodbye.proto",
];
fs::create_dir_all(OUT_DIR).unwrap();
tonic_build::configure()
.build_server(true)
.out_dir(OUT_DIR)
.compile(&protos, &["proto/"])?;
rerun(&protos);
Ok(())
}
fn rerun(proto_files: &[&str]) {
for proto_file in proto_files {
println!("cargo:rerun-if-changed={}", proto_file);
}
}
首先，声明了我们要编译的 proto 文件，随后创建 proto 文件编译后的输出位置（默认在 target/build 目录下）；
最后，使用 tonic_build 编译了 server 端的文件；
项目编译后，被编译的 proto 文件会输出至我们定义好的 src/proto-gen 下；
tonic-demo/src/proto-gen/basic.rs
#[derive(Clone, PartialEq, ::prost::Message)]
pub struct BaseResponse {
#[prost(string, tag = "1")]
pub message: ::prost::alloc::string::String,
#[prost(int32, tag = "2")]
pub code: i32,
}
tonic-demo/src/proto-gen/hello.rs
#[derive(Clone, PartialEq, ::prost::Message)]
pub struct HelloRequest {
#[prost(string, tag = "1")]
pub name: ::prost::alloc::string::String,
}
#[derive(Clone, PartialEq, ::prost::Message)]
pub struct HelloResponse {
#[prost(string, tag = "1")]
pub data: ::prost::alloc::string::String,
#[prost(message, optional, tag = "2")]
pub message: ::core::option::Option<super::basic::BaseResponse>,
}
/// Generated client implementations.
pub mod hello_client {
#![allow(unused_variables, dead_code, missing_docs, clippy::let_unit_value)]
use tonic::codegen::*;
use tonic::codegen::http::Uri;
#[derive(Debug, Clone)]
pub struct HelloClient<T> {
inner: tonic::client::Grpc<T>,
}
impl HelloClient<tonic::transport::Channel> {
/// Attempt to create a new client by connecting to a given endpoint.
pub async fn connect<D>(dst: D) -> Result<Self, tonic::transport::Error>
where
D: std::convert::TryInto<tonic::transport::Endpoint>,
D::Error: Into<StdError>,
{
let conn = tonic::transport::Endpoint::new(dst)?.connect().await?;
Ok(Self::new(conn))
}
}
impl<T> HelloClient<T>
where
T: tonic::client::GrpcService<tonic::body::BoxBody>,
T::Error: Into<StdError>,
T::ResponseBody: Body<Data = Bytes> + Send + 'static,
<T::ResponseBody as Body>::Error: Into<StdError> + Send,
{
pub fn new(inner: T) -> Self {
let inner = tonic::client::Grpc::new(inner);
Self { inner }
}
pub fn with_origin(inner: T, origin: Uri) -> Self {
let inner = tonic::client::Grpc::with_origin(inner, origin);
Self { inner }
}
pub fn with_interceptor<F>(
inner: T,
interceptor: F,
) -> HelloClient<InterceptedService<T, F>>
where
F: tonic::service::Interceptor,
T::ResponseBody: Default,
T: tonic::codegen::Service<
http::Request<tonic::body::BoxBody>,
Response = http::Response<
<T as tonic::client::GrpcService<tonic::body::BoxBody>>::ResponseBody,
>,
>,
<T as tonic::codegen::Service<
http::Request<tonic::body::BoxBody>,
>>::Error: Into<StdError> + Send + Sync,
{
HelloClient::new(InterceptedService::new(inner, interceptor))
}
/// Compress requests with the given encoding.
///
/// This requires the server to support it otherwise it might respond with an
/// error.
#[must_use]
pub fn send_compressed(mut self, encoding: CompressionEncoding) -> Self {
self.inner = self.inner.send_compressed(encoding);
self
}
/// Enable decompressing responses.
#[must_use]
pub fn accept_compressed(mut self, encoding: CompressionEncoding) -> Self {
self.inner = self.inner.accept_compressed(encoding);
self
}
pub async fn hello(
&mut self,
request: impl tonic::IntoRequest<super::HelloRequest>,
) -> Result<tonic::Response<super::HelloResponse>, tonic::Status> {
self.inner
.ready()
.await
.map_err(|e| {
tonic::Status::new(
tonic::Code::Unknown,
format!("Service was not ready: {}", e.into()),
)
})?;
let codec = tonic::codec::ProstCodec::default();
let path = http::uri::PathAndQuery::from_static("/hello.Hello/Hello");
self.inner.unary(request.into_request(), path, codec).await
}
}
}
/// Generated server implementations.
pub mod hello_server {
#![allow(unused_variables, dead_code, missing_docs, clippy::let_unit_value)]
use tonic::codegen::*;
/// Generated trait containing gRPC methods that should be implemented for use with HelloServer.
#[async_trait]
pub trait Hello: Send + Sync + 'static {
async fn hello(
&self,
request: tonic::Request<super::HelloRequest>,
) -> Result<tonic::Response<super::HelloResponse>, tonic::Status>;
}
#[derive(Debug)]
pub struct HelloServer<T: Hello> {
inner: _Inner<T>,
accept_compression_encodings: EnabledCompressionEncodings,
send_compression_encodings: EnabledCompressionEncodings,
}
struct _Inner<T>(Arc<T>);
impl<T: Hello> HelloServer<T> {
pub fn new(inner: T) -> Self {
Self::from_arc(Arc::new(inner))
}
pub fn from_arc(inner: Arc<T>) -> Self {
let inner = _Inner(inner);
Self {
inner,
accept_compression_encodings: Default::default(),
send_compression_encodings: Default::default(),
}
}
pub fn with_interceptor<F>(
inner: T,
interceptor: F,
) -> InterceptedService<Self, F>
where
F: tonic::service::Interceptor,
{
InterceptedService::new(Self::new(inner), interceptor)
}
/// Enable decompressing requests with the given encoding.
#[must_use]
pub fn accept_compressed(mut self, encoding: CompressionEncoding) -> Self {
self.accept_compression_encodings.enable(encoding);
self
}
/// Compress responses with the given encoding, if the client supports it.
#[must_use]
pub fn send_compressed(mut self, encoding: CompressionEncoding) -> Self {
self.send_compression_encodings.enable(encoding);
self
}
}
impl<T, B> tonic::codegen::Service<http::Request<B>> for HelloServer<T>
where
T: Hello,
B: Body + Send + 'static,
B::Error: Into<StdError> + Send + 'static,
{
type Response = http::Response<tonic::body::BoxBody>;
type Error = std::convert::Infallible;
type Future = BoxFuture<Self::Response, Self::Error>;
fn poll_ready(
&mut self,
_cx: &mut Context<'_>,
) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
fn call(&mut self, req: http::Request<B>) -> Self::Future {
let inner = self.inner.clone();
match req.uri().path() {
"/hello.Hello/Hello" => {
#[allow(non_camel_case_types)]
struct HelloSvc<T: Hello>(pub Arc<T>);
impl<T: Hello> tonic::server::UnaryService<super::HelloRequest>
for HelloSvc<T> {
type Response = super::HelloResponse;
type Future = BoxFuture<
tonic::Response<Self::Response>,
tonic::Status,
>;
fn call(
&mut self,
request: tonic::Request<super::HelloRequest>,
) -> Self::Future {
let inner = self.0.clone();
let fut = async move { (*inner).hello(request).await };
Box::pin(fut)
}
}
let accept_compression_encodings = self.accept_compression_encodings;
let send_compression_encodings = self.send_compression_encodings;
let inner = self.inner.clone();
let fut = async move {
let inner = inner.0;
let method = HelloSvc(inner);
let codec = tonic::codec::ProstCodec::default();
let mut grpc = tonic::server::Grpc::new(codec)
.apply_compression_config(
accept_compression_encodings,
send_compression_encodings,
);
let res = grpc.unary(method, req).await;
Ok(res)
};
Box::pin(fut)
}
_ => {
Box::pin(async move {
Ok(
http::Response::builder()
.status(200)
.header("grpc-status", "12")
.header("content-type", "application/grpc")
.body(empty_body())
.unwrap(),
)
})
}
}
}
}
impl<T: Hello> Clone for HelloServer<T> {
fn clone(&self) -> Self {
let inner = self.inner.clone();
Self {
inner,
accept_compression_encodings: self.accept_compression_encodings,
send_compression_encodings: self.send_compression_encodings,
}
}
}
impl<T: Hello> Clone for _Inner<T> {
fn clone(&self) -> Self {
Self(self.0.clone())
}
}
impl<T: std::fmt::Debug> std::fmt::Debug for _Inner<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{:?}", self.0)
}
}
impl<T: Hello> tonic::server::NamedService for HelloServer<T> {
const NAME: &'static str = "hello.Hello";
}
}
需要注意的是：
为客户端生成的HelloClient类型：
为服务端生成的 HelloServer类型：
impl<T: Hello>，因此要求必须实现我们定义的 Hello Trait；<br/>
下面我们在 lib.rs 中引入 ptoroc 生成的文件：
lib.rs
pub mod basic {
include!("./proto-gen/basic.rs");
}
pub mod hello {
include!("./proto-gen/hello.rs");
}
pub mod goodbye {
include!("./proto-gen/goodbye.rs");
}
这里使用了标准库提供的 include! 将文件引入；
如果你没有定义 proto 文件编译后的输出位置，则默认在 target/build 目录下；
此时也可以使用 tonic 提供的 include_proto!("hello") 宏，直接引入对应文件而不用额外制定路径了；
参考官方文档：
<br/>
下面来实现服务端；
服务端的实现和其他语言基本类似，为对应 proto 定义的 Service 创建相应的 Service 实现即可：
tonic-demo/src/bin/server.rs
#[derive(Default)]
pub struct HelloService {}
#[tonic::async_trait]
impl Hello for HelloService {
async fn hello(&self, req: Request<HelloRequest>) -> Result<Response<HelloResponse>, Status> {
println!("hello receive request: {:?}", req);
let response = HelloResponse {
data: format!("Hello, {}", req.into_inner().name),
message: Some(BaseResponse {
message: "Ok".to_string(),
code: 200,
}),
};
Ok(Response::new(response))
}
}
#[derive(Default)]
pub struct GoodbyeService {}
#[tonic::async_trait]
impl Goodbye for GoodbyeService {
async fn goodbye(
&self,
req: Request<GoodbyeRequest>,
) -> Result<Response<GoodbyeResponse>, Status> {
println!("goodbye receive request: {:?}", req);
let response = GoodbyeResponse {
data: format!("Goodbye, {}", req.into_inner().name),
message: Some(BaseResponse {
message: "Ok".to_string(),
code: 200,
}),
};
Ok(Response::new(response))
}
}
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let addr = "0.0.0.0:50051".parse()?;
println!("server starting at: {}", addr);
Server::builder()
.add_service(HelloServer::new(HelloService::default()))
.add_service(GoodbyeServer::new(GoodbyeService::default()))
.serve(addr)
.await?;
Ok(())
}
在对应的 Trait 中实现接口的相应逻辑，最后在 main 中注册 Service 即可，逻辑非常清晰；
<br/>
客户端的实现就更加的简单了，首先通过地址创建 Endpoint 连接，随后直接调用对应函数即可：
tonic-demo/src/bin/client.rs
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let addr = Endpoint::from_static("https://127.0.0.1:50051");
let mut hello_cli = HelloClient::connect(addr.clone()).await?;
let request = Request::new(HelloRequest {
name: "tonic".to_string(),
});
let response = hello_cli.hello(request).await?;
println!("hello response: {:?}", response.into_inner());
let mut goodbye_cli = GoodbyeClient::connect(addr).await?;
let request = Request::new(GoodbyeRequest {
name: "tonic".to_string(),
});
let response = goodbye_cli.goodbye(request).await?;
println!("goodbye response: {:?}", response.into_inner());
Ok(())
}
是不是非常的简单；
<br/>
下面来测试一下，首先启动服务端：
$ cargo run --bin server
server starting at: 0.0.0.0:50051
再启动客户端：
$ cargo run --bin client
hello response: HelloResponse { data: "Hello, tonic", message: Some(BaseResponse { message: "Ok", code: 200 }) }
goodbye response: GoodbyeResponse { data: "Goodbye, tonic", message: Some(BaseResponse { message: "Ok", code: 200 }) }
客户端收到响应，并且服务端打出日志：
hello receive request: Request { metadata: MetadataMap { headers: {"te": "trailers", "content-type": "application/grpc", "user-agent": "tonic/0.8.3"} }, message: HelloRequest { name: "tonic" }, extensions: Extensions }
goodbye receive request: Request { metadata: MetadataMap { headers: {"te": "trailers", "content-type": "application/grpc", "user-agent": "tonic/0.8.3"} }, message: GoodbyeRequest { name: "tonic" }, extensions: Extensions }
在 Github Action 中需要添加步骤：
- name: Install protoc
run: sudo apt-get install -y protobuf-compiler
安装 protoc；
参考代码：
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可以看到，相比于其他语言来说，在 Rust 中使用 grpc 更加的简单，甚至不需要额外的去编写 protoc 生成的 shell 脚本，而是通过 build.rs 更加优雅的实现了！
更多tonic使用方法：
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源代码：
开源库：
参考文章：
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